NICOTINIC MODULATION OF DOPAMINE RELEASE STUDIED WITH A CHANNEL-BASED BIOSENSOR

描述（由申请人提供）：多巴胺释放的调节是滥用药物可能劫持奖励回路并导致成瘾的一种方式。例如，尼古丁通过多巴胺能神经元突触前末梢上的烟碱受体直接调节多巴胺的释放。然而，目前的方法来监测多巴胺的释放及其调制缺少一个重要的时空灵敏度，这是理所当然的快速递质突触，如谷氨酸和GABA突触。配体门控通道的目标细胞在快速突触允许忠实地检测单量子的时间分辨率低于1毫秒。这一水平的分辨率是不可能与当前的电化学和光学技术，应用于多巴胺突触，激活G蛋白偶联受体，而不是离子型受体。在这里，我们建议异源引入无脊椎动物配体门控多巴胺通道到啮齿动物多巴胺神经元的突触后靶点。这将使我们能够研究多巴胺的释放和尼古丁对多巴胺释放的调节，其时空分辨率通常为快速突触保留。我们预计，这种新的方法将填补我们对滥用物质的作用的理解的重要空白，并可能导致新的治疗策略。

DESCRIPTION (provided by applicant): Modulation of dopamine release is one way that drugs of abuse likely hijack reward circuitry and lead to addiction. For instance, nicotine directly modulates dopamine release through nicotinic receptors on presynaptic terminals of dopaminergic neurons. However, current methodologies to monitor dopamine release and its modulation are missing an important level of spatiotemporal sensitivity that is taken for granted at fast transmitter synapses like glutamate and GABA synapses. Ligand-gated channels on target cells at fast synapses allows faithful detection of single quanta with temporal resolution below 1 ms. This level of resolution is not possible with current electrochemical and optical techniques that are applied to dopamine synapses, which activate G protein coupled receptors rather than ionotropic receptors. Here we propose to heterologously introduce an invertebrate ligand-gated dopamine channel into postsynaptic targets of rodent dopamine neurons. This will allow us to study dopamine release and nicotinic modulation of dopamine release with spatiotemporal resolution typically reserved for fast synapses. We anticipate that this new methodology will fill an important gap in our understanding of the actions of abused substances and may lead to new therapeutic strategies.